Plots show standard graphical output from by gam.check() from the mgcv package, providing an assessment of model residuals. Note the R2 values at the top of each set of plots, taken from the table on the previous tab.
Results for each station evaluate windows from 5 - 15 years with seasonal summaries in quarters. Trends are assessed for average estimated values of each indicator within the seasonal range shown at the top of each plot. * p < 0.05, ** p < 0.005